No abstract

Finer grained micritic limestone; orange wisps and dark flecks of dolomitic limestone; no areas with porosity observed 281.0 White biomicritic limestone; corals at this level 299.0 Biomicritic limestone, some areas with grain support; moldic porosity; gastropods abundant; white limestone; some molds filled with spar; some shell fragments; areas with sporadic grainstone; some grains appear to be fossils or ooids(?) 302.1-324.8 White, biomicritic limestone; heavy moldic porosity; large vugs; well-developed molds; abundant gastropods; areas of grain support 324.8-325.0 Biomicritic limestone; moldic porosity not connected; white, finely disseminated shell fragments; spar-filled shell fragments 325.0 Lower Glen Rose Limestone and Bexar Shale Member of the Pearsall Formation contact; micritic limestone; rip-up clasts; vugs filled with spar; shell molds filled with spar; minor moldic porosity; vug-filled with clay; probably an erosional surface; vug-filling highly calcareous 325.0-326.5 Light-gray microspar matrix with large grains of spar; some vug-filled spar; oyster fragments increasing in size downhole; minor intercrystalline porosity 327.9 Light-gray micritic matrix; large spar grains touching in areas; minor intercrystalline porosity; spar in-filling; some fractures; shell fragments 329.0 Gray micritic limestone with areas of microspar; very abundant spar grains in many areas appear to be grain supported; minor moldic porosity not connected; no intercrystalline porosity; shell fragments; light-gray to white mottled 330.0 Gray to light-gray, micritic limestone with interspersed microspar; shell fragments replaced with spar; abundant rip-up clasts; small amount of nonconnected moldic porosity 330.3 Gray, microspar-rich limestone; oyster and other shell fragments; most fragments replaced with spar; some rip-up clasts of micrite; most molds filled with spar; some open molds; clast size and abundance increase upward; clasts mostly spar grains 331.0 Gray-mottled, microspar-rich limestone; areas of spotty dolomitic limestone; grading into limestone at 330.3 feet; shell fragment abundance increases from 331-330.3 feet; particle size increases between 330.3 to 331.0 feet; intercrystalline porosity 332.0 Gray mottled microspar-dolomite; small shell fragments; intercrystalline porosity; isolated larger spar grains; some moldic and small-vug porosity 332.8 Gray mottled dolomitic clasts; microspar dolomitic limestone; soft-sediment deformation; intercrystalline porosity; particle size increases with larger grains of spar; shell fragments increase to whole shells uphole at 332.

Top right, Sauropod tracks in the Blanco River channel approximately 2.9 miles west of the town of Blanco near the stratotype location for the Corbula marker bed.

Analyses of veins. breccia. and massive sulfide deposits. .

The δ values for stable-isotope ratios discussed in this report are referenced to the following standard materials: Element R Standard identity and reference hydrogen hydrogen-2/hydrogen-1 Vienna-Standard Mean Ocean Water (Fritz and Fontes, 1980) oxygen oxygen-18/oxygen-16 Vienna-Standard Mean Ocean Water (Fritz and Fontes, 1980)